Guild Wars 2

I don’t completely understand what happened here. I’m joining PUGs to try and get the Faster Than Light achievement. I was doing good on this run until the lasers suddenly stopped when the mesmer exited the party. Our party did not wipe. The mesmer in the party later explains s/he had been relogging to regain health. This is some kind of abuse of the system isn’t it? I can provide video to the whole session but this highlight is the most important.

http://www.twitch.tv/guildwars2live/c/2483979

0:32 downed mesmer exits and lasers stop, we’re locked in the room (stuck in combat)
1:25 mesmer returns to the party, appears dead at dungeon entrance
2:24 mesmer portrait goes blank
2:55 mesmer re-emerges at entrence with full health
4:44 mesmer reaches NPC and re-starts Frizz battle
7:30 downed mesmer exits
8:35 mesmer returns at the entrance of dungeon
10:36 mesmer enters laser room while it continues

I would be fairly unhappy if tomorrow more people are doing this selfishly because they lost their opportunity at the FTL achievement and want it to reset. The other party members wanted to legitimately complete the dungeon.